xgboost/src/tree/updater_sync.cc
2016-01-16 10:24:01 -08:00

53 lines
1.4 KiB
C++

/*!
* Copyright 2014 by Contributors
* \file updater_sync.cc
* \brief synchronize the tree in all distributed nodes
*/
#include <xgboost/tree_updater.h>
#include <vector>
#include <string>
#include <limits>
#include "../common/sync.h"
#include "../common/io.h"
namespace xgboost {
namespace tree {
DMLC_REGISTRY_FILE_TAG(updater_sync);
/*!
* \brief syncher that synchronize the tree in all distributed nodes
* can implement various strategies, so far it is always set to node 0's tree
*/
class TreeSyncher: public TreeUpdater {
public:
void Init(const std::vector<std::pair<std::string, std::string> >& args) override {}
void Update(const std::vector<bst_gpair> &gpair,
DMatrix* dmat,
const std::vector<RegTree*> &trees) override {
if (rabit::GetWorldSize() == 1) return;
std::string s_model;
common::MemoryBufferStream fs(&s_model);
int rank = rabit::GetRank();
if (rank == 0) {
for (size_t i = 0; i < trees.size(); ++i) {
trees[i]->Save(&fs);
}
}
fs.Seek(0);
rabit::Broadcast(&s_model, 0);
for (size_t i = 0; i < trees.size(); ++i) {
trees[i]->Load(&fs);
}
}
};
XGBOOST_REGISTER_TREE_UPDATER(TreeSyncher, "sync")
.describe("Syncher that synchronize the tree in all distributed nodes.")
.set_body([]() {
return new TreeSyncher();
});
} // namespace tree
} // namespace xgboost